The present invention relates to a new and distinct cultivar of mock orange that is grown as a shrub in the landscape. The new cultivar is known botanically as Philadelphus×hybrida and will be referred to hereinafter by the cultivar name ‘STARBRIGHT’.
‘STARBRIGHT’ was selected by the inventor in Vancouver, British Columbia, Canada, in 1995 for unique foliage and calyx color. The new cultivar ‘STARBRIGHT’ is a hybrid plant that resulted from cross-pollination breeding project begun in 1990 and conducted by the inventor in a cultivated area of Vancouver, British Columbia, Canada. Reciprocal crosses were made using emasculated flowers of an individual plant of seed parent Philadelphus delavayi ssp melanocalyx (unpatented) and an individual plant of pollen parent Philadelphus lewisii (unpatented).
‘STARBRIGHT’ is a deciduous shrub characterized by the bronzy-purple newly emerging foliage and a purplish-black calyx. It is smaller in height and more hardy than its parent Philadelphus delavayi and has larger flowers than its parent Philadelphus lewisii. This combination of the characteristics of foliage color, size, hardiness and flower size distinguish ‘STARBRIGHT’ from all other Philadelphus known to the inventor.
‘STARBRIGHT’ resembles its seed parent Philadelphus delavayi ssp. melanocalyx but differs in that the parent has a hardiness rating of USDA Zone 6 while the resulting hybrid is hardy to USDA Zone 3, greatly expanding the range of this plant. Flower size of ‘STARBRIGHT’ is larger than the flower size of either parent. Plant height of ‘STARBRIGHT’ is lower than Philadelphus delavayi. Petals of ‘STARBRIGHT’ overlap while those of the lewsii parent have a gap between the petals. No seedlings have ever arisen from this hybrid which appears to be sterile.
The first asexual reproduction of ‘STARBRIGHT’ was conducted by the inventor in 1996 in a cultivated area of Vancouver, British Columbia, Canada. The method used for asexual propagation was semi-hardwood cuttings. Since that time the inventor has determined that distinguishing characteristics of ‘STARBRIGHT’ are stable and are reproduced true to type in successive generations of asexual reproduction.